1. Field of the Invention
The subject invention relates to the packaging of electronic sensing circuitry for use in automotive engine applications.
2. Prior Art
The typical automotive oil pressure sensor is a mechanically intensive device with many moving parts. An example of such a device includes a housing encompassing circuitry within the housing. The housing includes a threaded portion at one end for threadably engaging an engine and a cavity portion at the other end for receiving a wiring harness.
The problem with such devices is that the transducer comprises many moving parts and sliding contacts which are subject to vibration and corrosion. Such transducers displace a large volume of air, making waterproofing difficult. These devices are also lengthy and bulky. Further, many of these devices cannot be installed in an engine by use of a deep well socket. In addition, the typical electronic pressure sensor is not satisfactory for the rugged automotive under-hood environment.
Others have attempted various solutions to the above problems. One example is U.S. Pat. No. 4,590,400 to Shukla et al. which discloses a piezoelectric cylinder pressure transmitter.
U.S. Pat. No. 4,163,964 to De Filippis discloses a pneumatic or hydraulic pressure sensors with several thresholds of response.
U.S. Pat. No. 4,320,664 to Rehn et al. discloses a thermally compensated silicon pressure sensor.
U.S. Pat. No. 4,567,395 to Pundarika discloses a piezoelectric pressure transmitter for an internal combustion engine.
U.S. Pat. No. 4,570,097 to Shukla et al. discloses electrical connections for a piezoelectric pressure transmitter for an internal combustion engine.
U.S. Pat. No. 4,620,438 to Howng discloses a cylinder pressure transmitter for an internal combustion engine.
U.S. Pat. No. 4,616,114 to Strasser discloses a pressure responsive switch having little or no differential between actuation release pressure levels.
U.S. Pat. No. 4,633,579 to Strasser discloses a method for making a pressure responsive switch.
U.S. Pat. No. 4,645,965 to Paganelli discloses a cylinder pressure transmitter for an internal combustion engine.